Protector.



J. F.EBER T. PROTECTOR.

APPLICATION FILED APR.I8.19I6.

1,295,714, I Patented Feb. 25, 1919.

J OSEPI-I FRANCIS EIBERT, OF NEW YORK, N. Y.

PROTECTOR.

Application filed April 18.

To all whom it may concern,

Be it known that I, JOSEPH FRANCIS EBERT, a citizen of the UnitedStates, residing at New York, in the county of New York and State of NewYork, have invented certain new and useful Improvements in Protectors,of which the following is a full, clear, concise, and exact description.7

This invention relates to devices designed to protect electric circuitsand apparatus from abnormal currents, such as high potential electricityor lightning.

In protectors it is common practice to have a pair of opposingelectrodes maintained electrically, separate by means of a dielectricwhich is usually a sheet of mica. In protectors having a small air-gapthe use of mica is objectionable, if not impossible, because of theditliculty from a commercial standpoint to hold a very thin sheetthereof to a uniform thickness. Due to the characteristics of mica, theloss resulting from working it into perfect dielectrics is very high.This waste factor adds considerable to the cost of mica dielectrics. Itis the object of this invention to provide a comparat'ively cheapdielectric material equally as efficient asmica.

The dielectric contemplated by this invention comprises a piece ofinsulating material or composition made of constituents having a mineralorigin and held together by a suitable binding agent. These constituentsmay consist of powdered or granular mica and talc held together by asuitable cement. The composition formed by these ingredients may haveone of the side portions cut away approximatel to the center, whichafi'ords passage for t e discharge of electricity thereacross throughair.

In-the accompanying drawings, Figure 1 is a perspective of a prqtectorembodying the features of this invention; and Fig. 2 is a side elevationof the dielectric of the invention.

Interposedbetween a pair of electrodes 1-1, such as carbon blocks, "is adielectric 2. One side of the dielectric 2 is cut away preferably asshown at 3. The cut-away portion of the dielectric allows the passage ofthe discharge of electricity thereacross through the air, and when theelectrodes 11 are of carbon, also permits the disintegrated. particlesof the carbon usually caused by such a discharge, to fall from be-Specification of Letters Patent.

Patented Feb. 25, 1919.

1916. Serial 1V0. 91.926.

tween the electrodes 1-1 whenthe protector shown in Fig. 1 is placed ina horizontal position. The dielectric 2 may comprise a piece ofinsulating material made of powdered or granular mica and talc heldtogether by a suitable binding agent such as shellac, etc. In case micaand talc mixed wlth shellac are used for the dielectric, these materialsmay be mixed dry in anyv conyement manner and then formed into sheets inaccordance with any approved method, such as being assed repeatedlybetween heated rolls an finally delivered upon a 0901] table. Thesesheets may then be sizcc ;0 any dimensions corresponding to those of thedielectrics used in standard forms of protectors. The protector shown inFig. 1 may be held in place in a circuit in any well-known manner.

From the above it is obvious that a dielectric embodying the features ofthis invention may consist of an insulating material made entirely ofeither granular mica or talc, or said material may comprise acomposition made of both of these substances having a greater or lesspercentage of either. While the preferred embodiment of this inventionhas been herein particularly shown and described, many modifications mayreadily be made without departin from the spirit of this invention.

at is claimed is:

' 1. In ahigh potential electricity protector, suitable electrodesopposing each other, and .a thin dielectric of uniform thicknessinterposed between said electrodes, said dielectr1c comprlsing acomposition consisting of mica and talc reduced to a very fine state ofsub-division and bound together by a suitable binding agent.

2. In a high potential electricity protector, suitable electrodesopposing each other, and

a thin dielectric of uniform thickness inter-- posed between saidelectrodes, said dielectric comprising a piece of insulating materialmade of constltuents reduced to a very fine state of subdivision andhaving a mineral origin, said particles being held together by asuitable binding agent.

3. In a high potential electricity protector, suitable electrodesopposing each other, and a thin dielectric of uniform thicknessinterposed between said electrodes, said dielectric comprising a pieceof insulating material made of constituents reduced to a very 4. In ahigh potentlal electricity protector, suitable electrodes opposing eachother, and

a thin dielectric of uniform thickness inter-' posed between saidelectrodes, said dielectric comprislng a piece of insulating materialmade of constituents reduced to a very fine state of subdivision, saidmaterial being substantially non-heat softenable.

5.1n a high potential electricity protector suitable electrodes opposingeach other, and

a thin dielectric of uniform thickness inter posed betweenvsaldelectrodes, said dielectric comprising a piece of insulatin materialmade of mineralronstituents re need to a very fine state of subdivisionand held toasagna gether by a suitable binding agent, said insulatingmaterial having a side portion thereof cut away approximately to thecenter.

6-. In a high potential electricity protector, suitable electrodesopposing each other, and

a thin dielectric of uniform thickness interposed between saidelectrodes, said dielectric comprising a. piece of insulating materialmade of mineral constituents reduced to a very fine state of subdivisionand held together by a suitable binding agent, said insulating-materialhaving provision for permitting the discharge of electricity thereacrossthrough air.

In Witness whereof, I hereunto subscribe my name this th day of April,A, D. 1916.

' JOSEPH FRANCIS EBERT.

